Speed regulator



g- 1956 J. A, TROENDLE SPEED REGULATOR Filed Dec. 18, 1951 ATTORNEY E w R 3 m0 m A M a United States Patent SPEED REGULATOR Jean A. Troendle, Hollywood, Calif.

Application December 18, 1951, Serial N 0. 262,305

6 Claims. (Cl. 242-75) This invention relates to improved speed regulators for controlling the speed of removal of material from a roll.

In recording oscillographs it is common practice to record data photographically or with a stylus on sensitized paper or film which is caused to move through the recording apparatus while information is being recorded. In many applications of such oscillographs it is desirable to regulate the speed of the recording medium so that it moves at a substantially constant speed while the information is being recorded.

In a typical recording oscillograph, the information to be recorded is represented by electric currents which are applied to galvanometers, and the galvanometers move small mirrors which direct beams of light on sensitized recording paper. The recording paper is pulled from a large roll of the paper by a driven roller, and a metering roller is located between the roll of paper and the driven roller. The beams of light from the galvanometers are projected onto the paper as it passes over the metering roller.

Ordinarily the speed at which the recording paper moves is controlled by controlling speed of the recording paper over the metering roller. Such an arrangement requires some kind of braking means for the supply roll in addition to the speed regulator which cooperates with the metering roller. Also, a large motor is required to rotate the driven roller because the motor must pull against both the brake on the supply roll and the braking effect of the speed regulator which cooperates with the metering roller.

If the paper is wormd around the driven roller, it is difiicult to maintain the speed of the paper constant by regulating the rate of rotation of the driven roller because the effective diameter of the driven roller increases as the paper is wound around it.

These difiiculties are overcome in my invention by regulating the speed of the recording paper by a speed regulator which acts upon the outer periphery of the supply roll of the paper. Such an arrangement regulates the speed at which the paper is removed from the supply roll and it is not affected by the effective diameter of either the driven or the supply roll. The control arrangement is simplified, and a small motor may be employed since it pulls against only one braking action, i. e. that of the speed regulator. Moreover, during the starting period, no braking effect is present so that the desired operating speed is attained rapidly.

In accordance with my invention an auxiliary roller is provided which is pressed against the outer periphery of the supply roll of paper, and the auxiliary roller is connected to apparatus for controlling the rate of rotation of the auxiliary roller.

In a preferred embodiment of the invention the rate of rotation of the auxiliary roller is controlled by a centrr'fugal regulator which increases the torque required to rotate the auxiliary roller when the rate of rotation of the auxiliary roller exceeds a certain value. If desired, the centrifugal regulator can be employed to actuate electrical circuits which increase the starting torque of the motor-which rotates the driven roller, so as to minimize 2,757,873 Patented Aug. 7, 1956 the time required to attain the desired operating speed for the recording paper.

The invention is explained with reference to the drawings, inwhich:

Fig. 1 shows in schematic form the speed regulator arrangement of the present invention employed in a conventional paper feeding apparatus; and

Fig. 2 shows a sectional view of a preferred embodiment of the speed regulator, and a schematic diagram of an electric circuit which may be connected to the speed regulator.

Fig. 1 shows the speed regulator arrangement of the invention wherein a roller 10 of a speed regulator, which is supported by a hinge 12, is pressed against the outer periphery of a supply roll 14 of recording paper by a spring 18.

The recording paper 16 passes over an idler roller 20 to a take-up roll 22 which is wound around a roller 24. The roller 24 is driven by an electric motor 26. Preferably, the motor 26 is a series wound type so that the torque of the motor increases as the speed of the motor decreases due to increases of the diameter of the roll 22.

The optical images representing the information to be recorded on the paper 16 should be projected onto the paper as it passes over the idler roller 20. Since the apparatus for producing the optical images is not part of the present invention, it is not shown in the drawings.

The roller 10 is connected to a speed regulator which increases the torque required to rotate the roller 10 when the rate of rotation of the roller 10 exceeds a certain value.

Since the rate of rotation of the roller 10 is determined by the surface speed of the supply roll 14 of paper, the speed at which the paper 16 is pulled over the idler roller 20 is governed by the speed regulator attached to the roller 10 and it is not aifected by the diameter of the supply roll 14 of paper or by the diameter of the take-up roll 22.

Fig. 2 shows a preferred type of speed regulator for use with the roller 10. It is an adjustable centrifugal type which operates by braking effect.

The roller 10 is mounted on a shaft 30 to which a pair of centrifugal arms 32 and 34 are connected by hinges 36 and 38. The arms 32 and 34 are channel members having weights 40 and 42 located at their ends.

A pair of braking members 44 and 46, which may be composed of cork for example, are secured to the centrifugal arms 32 and 34 about half way between the hinges and the weights.

The speed regulator is enclosed in a cylindrical housing 48 which has a cylindrical internal surface which the braking members 44 and 46 engage when the arms 32 and 34 are moved outwardly by centrifugal forces. The shaft 30 is rotatably mounted in a pair of bearings 54 and 56 which are aflixed to the housing, and the roller 10 extends through an opening in the housing. The hinge 12 is afiixed to the housing so that it straddles the roller 10.

A pair of arcuate springs 58 and 60 serve to force the arms 32 and 34 away from the cylindrical member 48, and the tension of the springs is controlled by a knob 62 which is supported by a shaft 64 having a threaded portion 66 which engages a corresponding internal thread 68 in the end of the shaft 30. Thus, the adjustable shaft 64 serves as an extension of the shaft 30, and the torque required to rotate the roller 10 at high speeds is determined by the position of the shaft 64.

As shown in Fig. 2, the supports for the springs are arranged with respect to the pivot points of the hinges 36 and 38 so that the leverage for the forces produced by the springs increases as the forces provided by the springs are increased by adjusting the knob 62.

In operation, rotation of the roller 10 causes the shaft 30, the arms 32 and 34, the shaft 64, and the knob 62 to rotate.

The rotation of the arms 32 and 34 causes the weighted ends of the arms to move outwardly because of the centrifugal forces. When the rate of rotation is sufficient to cause the braking members 44 and 46 to engage the interior surface of the cylindrical housing 48, the torque required to rotate the roller is increased due to the braking effect of the members 44- and 46.

Thus, the load on the motor 26 which pulls the recording paper is controlled by the speed regulator connected to the roller 10, and the speed of the recording paper is maintained substantially constant.

If desired, a pair of contacts 80 and 82 may be provided for controlling electrical apparatus such as the motor which pulls the recording paper.

The contact 80 is connected to the arm 34 so as to provide a good electrical circuit from the contact through the arm and its hinge to the shaft 30. The contact 82 is supported in an insulator 84 which is secured in an opening in the shaft 30. A longitudinal bore is provided in the shaft 30, and a wire 86 extends through the bore and connects the contact 82 with an annular slip-ring 88 which is mounted on an annular insulator 90 at the end of the shaft.

A cap 92 is provided on the end of the shaft 30. A brush 94, which rides on the cap 92, and a brush 96, which rides on the slip-ring 88, are employed to provide electrical connections to the contacts 80 and 82 while the shaft is rotating.

A battery 100 and the winding of a relay 102 are connected in series between the brushes, and the armature of the relay 102 is employed to connect an auxiliary Winding 104 in shunt with the stator winding 106 of the motor 26.

When the speed regulator is at rest, the contacts 80 and 82 are closed so that the relay 102 operates and connects the auxiliary winding 104 in shunt with the stator winding 106 of the motor. Thus, the motor 26 has a large starting torque when it is first energized.

When the speed regulator approaches its normal operating speed, the centrifugal forces cause contacts 80 and 82 to open and consequently the relay 102 is de-energized, thereby disconnecting the auxiliary Winding 104 and decreasing the torque of the motor.

In this manner, the speed regulator causes the starting time of the motor to be decreased and reduces the time required for the recording paper to attain the desired constant speed.

I claim:

1. Apparatus for controlling the speed at which material is removed from a rotatable roll, comprising a roller which contacts the outer periphery of the roll, and a centrifugal speed regulator attached to the roller for increasing the torque required to rotate the roller when the rate of rotation of the roller exceeds a predetermined value, the speed regulator providing substantially no increase in the torque required to rotate the roller until the rate of rotation of the roller exceeds said predetermined value.

2. Apparatus for controlling the removal of material from a rotatable roll, comprising a driven roller for removing material from the roll, a second roller contacting the outer periphery of the roll, and a centrifugal speed regulator coupled to the second roller for controlling the torque required to rotate the second roller when its rate of rotation exceeds a predetermined value.

3. ln apparatus for controlling the removal of material from a rotatable supply roll, having a first roller for engaging the material and unrolling it from the supply roll, a motor for driving the first roller, and a second roller contacting the outer periphery of the supply roll, the combination which comprises a centrifugal speed regulator connected to the second roller for controlling the torque required to rotate the second roller, the speed regulator having a pair of contacts which are normally closed and which open when the speed. of rotation of the second roller exceeds a predetermined value, and means 4 coupled between the contacts and the motor for decreasing the torque of the motor when the contacts open.

4. Apparatus for controlling the speed at which material is removed from a rotatable supply roll, comprising a roller which contacts the outer periphery of the supply roll, a rotatable shaft extending through the roller and secured thereto, an adjustable extension connected to one end of the shaft and rotatable therewith, a pair of centrifugal arms respectively pivoted at one end to the shaft at diametrically opposed locations around the shaft, spring means extending between the pivoted ends of the centrifugal arms and the adjustable extension of the shaft for forcing the other ends of the centrifugal arms toward the shaft, and means for increasing the torque required to rotate the shaft when centrifugal forces cause said other ends of the centrifugal arms to move away from the shaft a predetermined distance.

5. A speed regulator comprising a rotatable shaft, an adjustable extension connected to one end of the shaft and rotatable therewith, a pair of centrifugal arms respectively pivoted at one end to the shaft at diametrically opposed locations around the shaft, spring means extending between the pivoted ends of the centrifugal arms and the adjustable extension of the shaft for forcing the other ends of the centrifugal arms toward the shaft, means for increasing the torque required to rotate the shaft when centrifugal forces cause said other ends of the centrifugal arms to move away from the shaft a predetermined distance, a contact located adjacent said other end of one of the centrifugal arms and electrically connected therewith, a second contact located on the shaft opposite the first contact and electrically insulated from the shaft, a slipring located around the shaft and insulated therefrom, and a conductor connecting the slip-ring and the second contact.

6. In apparatus for controlling the removal of material from a rotatable supply roll, having a first roller for removing material from the supply roll, a motor for driving the first roller, an electrically operated speed control for the motor, and a second roller contacting the outer periphery of the supply roll, the combination which comprises a shaft coupled to the second roller, an adjustable extension connected to one end of the shaft and rotatable therewith, a pair of centrifugal arms respectively pivoted at one end to the shaft at diametrically opposed locations around the shaft, spring means extending between the pivoted ends of the centrifugal arms and the adjustable extension of the shaft for forcing the other ends of the centrifugal arms toward the shaft, a contact located adjacent said other end of one of the centrifugal arms and electrically connected therewith, a second contact located on the shaft opposite the first contact and electrically insulated from the shaft, means connecting said contacts to the speed control for the motor, a hollow cylindrical housing extending around the shaft, and braking members located on the centrifugal arms for engaging the inner surface of the housing when the speed of rotation of the shaft exceeds a predetermined value.

References Cited in the file of this patent UNITED STATES PATENTS 152,750 Johnston July 7, 1874 283,842 Wright Aug. 28, 1883 1,708,951 Obergfell Apr. 16, 1929 1,838,967 Staege Dec. 29, 1931 1,891,766 Johnstone et al. Dec. 20, 1932 1,904,089 Schwerin Apr. 18, 1933 1,941,473 Howell Ian. 2, 1934 2,095,307 Ball et a1 Oct. 12, 1937 2,416,973 Wright Mar. 4, 1947 2,493,897 Petz et al. Ian. 10, 1950 2,643,871 Warrick June 30, 1953 FOREIGN PATENTS 208,549 Germany Apr. 5, 1909 331,746 Great Britain July 10, 1930 

